Exhaust for outboard jet propulsion engine

ABSTRACT

An outboard jet drive marine system for a boat comprises a bucket assembly adapted to be mounted to a jet drive unit for receiving a water exhaust from a jet drive unit. The bucket assembly has a bucket housing. The bucket housing has a first exhaust, and at least a second exhaust. The second exhaust directs the water jet in a direction towards and beneath the boat. The bucket housing has an entrance port for receiving said water exhaust. A bucket is rotatably mounted on the bucket housing at the first exhaust and is rotatable relative to the first exhaust between an open position and a closed position. The bucket deflects water entering the entrance port to the at least a second exhaust when in a closed position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application is a Non-Prov of Prov (35 USC 119(e)) application ofProvisional Application No. 60/751,700 filed on Dec. 19, 2005.

BACKGROUND OF THE INVENTION

This invention is related to an exhaust for an outboard jet propulsionengine, and in particular, a bucket for exhausting the water jet whendriving the associated craft in the reverse direction.

It is known in the art to utilize an outboard jet propulsion engine todrive a boat. As known from applicant's co-pending U.S. application Ser.No. 10/988,327, filed Sep. 14, 2005 entitled OUTBOARD JET DRIVE MARINEPROPULSION SYSTEM (the “327 application”) water is driven through ahousing, the force of the exiting jet of water moving the boat in theforward direction. A bucket assembly is mounted at the jet exhaust so asto selectively move from a first position to a second position betweencovering the exhaust and keeping clear of the exhaust. As the bucketassembly covers an exiting water jet, it diverts the direction of thewater jet to move the boat in the reverse direction.

Making reference to FIGS. 1A and 4A, a prior art bucket assemblygenerally indicated as 10 includes bucket housing 12 adapted to bemounted downstream of the water jet exhaust of the jet drive unit. Abucket 14 is rotatably mounted on bucket housing 12 so as to selectivelyclose a first exhaust at an exit end of bucket housing 12 as seen inFIG. 2A. As the jet exiting the jet drive unit hits upon an interiorsurface 16 (FIG. 1A) of bucket 14, the water is blocked from exiting thefirst exhaust and is deflected through exhaust plenum 22 on either sideof bucket 14.

Plenums 22 extend from bucket 14 and are in communication with theinterior of bucket 14 on either side of bucket 14 (see FIGS. 1A and 3A)to also provide an escape for water deflected against interior backsurface 16 of bucket 14. The exhausts of plenum 22, are substantiallycoextensive with the bucket and exhaust water in a direction generallyback and towards the lower surface of housing 12 when bucket 14 is inthe closed position. In this way, water is pushed back towards the boathaving a net effect of pushing the boat in the reverse direction.

This structure has been satisfactory for reversing the boat under thecontrol of a jet propulsion engine. However, it suffers from thedisadvantage that power is lost when the engine is required to maketight turns in the reverse direction; particularly in the type ofmovements required by a tugboat, i.e., tight quick turns under highpower. As known from the '327 application, steering of a boat utilizingthe jet propulsion engine is accomplished by moving the direction of thejet, i.e., movement of the bucket and exhaust port about a pivot point30 relative to the remainder of the housing or the boat. During tightmaneuvers, one of plenums 22 became blocked by the structure of theboat, reducing the effective power of the engine. Additionally, waterjets exiting plenums 22 quickly lost their cohesion and in effect theirpower.

Furthermore, it was discovered that the gas exhaust from the enginehoused within the jet propulsion housing was producing bubbles as itexited the housing, which was interfering the optimal operation of thejet engine as a result of cavitation.

Accordingly, an improved bucket assembly and exhaust system is desiredwhich overcomes the deficiencies of the prior art.

BRIEF DESCRIPTION OF THE DRAWINGS

Objects, features of the present invention will be apparent from thewritten description in which:

FIG. 1A is a front perspective view of a bucket assembly constructed inaccordance with the prior art;

FIG. 1B is the comparable perspective view of a bucket assemblyconstructed in accordance with the invention;

FIG. 2A is a side elevational view of a bucket assembly constructed inaccordance with the prior art;

FIG. 2B is the comparable elevational view of a bucket assemblyconstructed in accordance with the invention;

FIG. 3A is a front perspective view showing a prior art bucket assembly;

FIG. 3B is a comparable front perspective view of a bucket assemblyconstructed in accordance with the invention;

FIG. 4A is a rear elevational view of a prior art bucket assembly in theclosed position;

FIG. 4B is a rear elevational view of a bucket assembly constructed inaccordance with the invention in the closed position;

FIG. 5 is a side elevational view of a bucket assembly mounted on a jetpropulsion engine in a substantially open position constructed inaccordance with the invention;

FIG. 6 is a rear perspective view of the housing and bucket assembly,constructed in accordance with the invention;

FIG. 7 is a side elevational view of the bucket assembly constructed inaccordance with the invention in the open position;

FIG. 8 is a first side elevational view of a housing and bucket assemblyconstructed in accordance with another embodiment of the invention;

FIG. 9 is a rear elevational view of the housing and bucket assembly inthe closed position constructed in accordance with the invention of FIG.8;

FIG. 10 is front elevational view of a housing and bucket assembly inthe closed position constructed in accordance with the invention of FIG.8;

FIG. 11 is a bottom plan view of the housing and bucket assembly in theclosed position constructed in accordance with the invention of FIG. 8;

FIG. 12 is a top plan view of the bucket assembly in the closed positionconstructed in accordance with the invention of FIG. 8;

FIG. 13 is a side elevational view of the opposite side of bucketassembly in a closed position constructed in accordance with theinvention of FIG. 8;

FIG. 14 is a sectional view taken along line 14-14 of FIG. 8. and

FIG. 15 is a first side elevational view of a housing and bucketassembly in the open position constructed in accordance with theinvention of FIG. 8.

DETAILED DESCRIPTION OF THE INVENTION

Reference is made to FIGS. 1B, 2B, 3B and 4B in which a bucket assembly,generally indicated as 100, is shown. Bucket assembly 100 includes abucket housing 104. A bucket 102 is rotatably mounted on bucket housing104. Bucket housing 104 is in communication with a water exhaust of thejet propulsion engine so as to receive water existing the water exhaust(not shown). Bucket housing 104 has an entrance port 106 and a firstexhaust 108 (FIG. 7), seen at an opposed end of housing 104 for allowingwater to exit bucket housing 104 when bucket 102 is in the openposition.

An exhaust assembly, generally indicated as 110, provides a secondexhaust. The exhaust assembly 110 has a first vent 112 and a second vent114. Vent 112 extends along a first axis and vent 114 extends along asecond access so that the first axis intersects the second axis, i.e.vent 114 is angled relative to vent 112. When bucket 102 blocks waterfrom exiting exhaust 108, it also places vents 114, 112 are incommunication with the interior of bucket housing 104 to allow water toexit when bucket 102 is in the closed position.

A bucket linkage 124 is connected to bucket 102. A reverse cable 126which controls linkage 124, rotates bucket 102 to a first position inwhich bucket 102 is open (FIG. 5, FIG. 6) to allow water to pass throughexit port 108. Linkage 124 also controls bucket 102 to move in adirection to close exit port 108 and redirect the water path throughfirst and second vents 112, 114 of bucket housing 104 to guide the waterin a direction substantially back towards the jet propulsion enginehousing 202.

In a preferred embodiment, bucket housing 104 has a substantiallycircular body. Vents 112, 114 are disposed along the circumference ofbucket housing 104, away from a bottom 140 of bucket housing 104 and onopposed sides of a pivot axis 119 extending through bucket housing 104.

The angle formed between vent 112 and vent 114 should be sufficient todivert water at an angle to flow around a boat to which exhaust assembly110 is attached. In a preferred non-limiting embodiment, the angleformed by the intersection of the axes along which vents 112 and 114 lieis about 34°. Accordingly, in the closed position, water enters buckethousing 104 in a direction towards bucket 102. When in the closedposition, water is deflected by bucket 102 substantially reversingdirection out through first and second vents 112, 114. When in the openposition, water will flow directly through exit port 108 of buckethousing 104.

Bucket 102 is substantially curved so as to be convex (FIG. 4) providingroom for water traveling through bucket housing 104 to travel towardsfirst and second vents 112, 114 as well as providing a surface whichfacilitates the substantially unimpeded deflection of water in thereverse direction; namely the convex curve.

First and second vents 112, 114 are in fluid communication with eachother when bucket 102 is in the closed position. Accordingly, if duringtight maneuvers either one of first and second vents 112, 114 becomesclosed against the jet unit structure, the pressure of the water exitingthe unblocked vent is increased. In this way, thrust sufficient toperform the tight maneuver is maintained. In this way, the jetpropulsion engine is self-adjusting.

Furthermore, bucket 102 includes a first plenum 130 and a second plenum132 in communication with the interior of bucket housing 120 to providea third exhaust for the water jet when bucket 102 is in the closedposition. Plenums 130, 132 preferably extend a length between extendingbeyond bucket 102 and to at least a bottom surface 140 of bucket housing104 when the housing is in a closed position.

Plenums 130, 132 substantially reside in a plane. Secondary exhausts112, 114 substantially reside in a second plan, the first planeintersecting the second plane at a substantially obtuse angle. In thisway, the water exiting the plenums 130, 132 and the secondary eventsavoid housing 200.

Furthermore, as the result of the longer plenum run, the jet remainsmore cohesive as it exits plenum 130, 132. Additionally, by releasingthe jet at a point at least at the bottom of bucket housing 104, theboat and/or housing are less likely to interface with the jet thrust,increasing overall thrust.

A secondary problem is cavitation that is air bubbles being trapped inthe jet stream intake. The air bubbles are formed from the exhaust ofthe engine from the housing.

Reference is now made to FIG. 7 in which structure for diverting airbubbles in accordance with another embodiment of the invention isprovided. A housing for an engine for driving the jet propulsion unit asknown from U.S. application Ser. No. 10/988,327 and incorporated as iffully detailed herein, generally indicated at 200, includes sidewalls202. Exhausts are formed as elongated channels 204 extending along alower portion of sidewall 202. Channels 204 are operatively coupled tothe exhaust of the engine of the jet propulsion system. In this way, thebubbles are diverted beyond the intake of the jet propulsion drive.

Reference is now made to FIGS. 8-15 in which an alternative embodimentof the invention is provided. The primary difference between the bucketassembly shown in this embodiment and those shown in FIGS. 1B-7, is thatthe vents 112, 114 have been replaced by an exhaust disposed within thebottom of the housing; the exhaust including vanes for directing thewater. As known from co-pending application U.S. Ser. No. 10/988,327,the bucket assembly is moved from the open to the closed position by avertical cable 126. However, it has been determined that in a preferredembodiment, the length of the cable, to achieve maximum result, must berelatively short given the length of the entire control assembly. In apreferred embodiment, the cable length extending in the verticaldirection is about three inches. Because of this small throw distance, abucket assembly must be designed to move the entire bucket so that theentire bucket is substantially clear of the output of the water jet whenthe bucket is in the open position to allow propulsion of the boat in aforward direction.

Furthermore, to reduce draft on the boat, it is desirable to have aventing mechanism for the housing which is not disposed on the outsideof the housing as with vents 112, 114. Accordingly, this embodiment is amore streamlined embodiment which still directs water back towards theboat to create reverse thrust but angles substantially all of theexiting water jet below the boat so as not to reduce the thrust of thewater jet.

Reference is now had to another embodiment of the bucket assembly,generally indicated as 300 and constructed in accordance with theinvention. Like structure is indicated by like numerals for ease ofdescription. Bucket assembly 300 includes a bucket housing 304, a bucket302 is rotatably mounted on bucket housing 304. Bucket housing 304 is incommunication with the water exhaust of the jet propulsion engine toreceive water exiting the water exhaust as described above. Buckethousing has an entrance port 106 and an exhaust 108 at an opposite endof bucket housing 304.

An exhaust assembly, generally indicated as 310 is formed with housing304. Exhaust assembly 310 includes an exhaust frame 314 and directionalvanes 316 and 318 disposed within frame 314. Vane 316 extends acrossframe 314 and is formed at an angle relative to the plane of the bottomof the boat (not shown) to form an angle of less than 90° therewith, butgreater than 1° so as to direct water exiting through exhaust 310towards the boat but below the plane in which the bottom of the boatresides. Frame 314 holds vanes 316, 318 in place so that the entireventing assembly 310 form a structure which is in fluid communicationwith the interior of housing 304. As seen in FIG. 14, vanes 316, 318intersect each other and form a plurality of first plenums 340.

During operation, water flows in the direction of arrow A throughhousing 304. When bucket 302 is in the closed position, it deflectswater in the direction of arrow B, as a result of its curved surfacetowards vanes 316, 318 (FIG. 14). Because of the curved surface ofbucket 302, water traveling in the direction of arrow B does notinterfere with water traveling in the direction of arrow A reducingturbulence and providing greater efficiency of thrust out of the bucketassembly in the direction substantially of arrow C back towards the boatand down. In this way, the jet stream used to propel in the reversedirection does not interfere with the boat. Additionally, water isdirected to the sides of the plenum (into the page and out of the pageof FIG. 14) to exit through first plenum 330 and a second plenum 332.

Bucket 302 includes a second plenum and a third plenum 332 incommunication with the interior of the bucket housing 304 to provide athird exhaust for the water jet when bucket 302 is in the closedposition. Plenum 330, 332 extend to be at least coextensive with thebucket 302 but a preferred embodiment extends a distance from beyondbucket 302 to at least a bottom surface 346, each plenum 330, 332 hasrespective exhaust opening 352, 354. Furthermore, plenums 330, 332 aretapered towards exhaust 352, 354.

Like plenums 130, 132, plenums 330, 332 are formed at an angle relativeto a bottom 346 of housing 304 to direct water existing plenum exhaust352, 354 towards the boat hull but down to avoid the jet from beingdeflected against the boat hull.

It should also be well understood, as shown in FIG. 15, when bucket 302is in the open position water moving in the direction of arrow A passesthrough exit port 108 and does not get deflected through plenum 340. Inthis way, the boat is pushed in the forward direction in accordance withthe invention.

It should be noted that plenums 330, 332 are formed of an outer wall 360of bucket assembly 302. A front wall 362 which may be formed of a singleunitary piece across the entire bucket assembly 302 or individualpieces, and an interior sidewall 364 which slides along frame 314(however, the outer wall of frame 314 may also be used to form a wall ofthe plenum). It is this entire assembly which is lifted when bucket 302is in the open position as shown in FIG. 15.

By providing vanes within frame 314 at the exhaust, there is a greatersurface area along the traveled path which focuses the water, cuts downon turbulence and increases the pressure of the exiting water.Similarly, by tapering plenums 330, 332, the pressure of the water isincreased as the cross section of the plenum decreases. Furthermore, thelonger the plenum, the more directed and focused the water columnbecomes exiting in the direction of arrow D (FIG. 14). Again,substantially in the direction towards, but down, relative to the boatto which the jet propulsion system is attached.

Thus, while there have been shown, described and pointed out novelfeatures of the present invention as applied to preferred embodimentsthereof, it will be understood that various omissions and substitutionsand change in the form and detail are contemplated so that the disclosedinvention may be made by those skilled in the art without departing fromthe spirit and scope of the invention. It is the intention therefore tobe limited only as indicated by the scope of the claims appended hereto.It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed and all statements of the scope of the invention, which as amatter of language, might be said to fall there between.

1. An outboard jet drive marine system for a boat comprising: a bucketassembly adapted to be mounted to a jet drive unit for receiving a waterexhaust from said jet drive unit, said bucket assembly having a buckethousing, said bucket housing having a first exhaust, and at least asecond exhaust; the at least second exhaust including a first vent and asecond vent mounted to said bucket housing, said bucket housing havingan entrance port for receiving said water exhaust, said first vent beingdisposed on the housing along a first axis and said second vent beingdisposed on the housing along a second axis, the first axis intersectingthe second axis; and a bucket rotatably mounted on said bucket housingat said first exhaust and being rotatable relative to said first exhaustbetween an open position and a closed position, said bucket deflectingwater entering said entrance port to said first and second vents when ina closed position.
 2. The outboard jet drive marine system for a boat ofclaim 1, wherein said bucket housing has a bottom, the first vent andsecond vent being disposed along a circumference of said bucket housingaway from the bottom.
 3. The outboard jet drive marine system for a boatof claim 1, further comprising a first plenum and a second plenum incommunication with the interior of said bucket, said first plenum andsaid second plenum extending to the bottom of said bucket housing whensaid bucket is in the closed position.
 4. The outboard jet drive marinesystem for a boat of claim 3, wherein each said plenum extends at asubstantially obtuse angle to said at least one of said first and secondvents.
 5. The outboard jet drive marine system of claim 1, wherein saidbucket causes said first vent to be in fluid communication with saidsecond vent, when said bucket is in the closed position.
 6. An outboardjet drive marine system for a boat comprising: a housing, said housinghaving side walls and a bottom, said housing adapted to be affixedbehind a hull of said boat; an engine disposed within said housing, saidengine having an exhaust; a jet drive unit mounted to said housing andbeing operatively coupled to said engine and said housing; and elongatedgrooves formed in the sidewall of said housing communicating with saidexhaust and being upstream of said jet drive unit.
 7. The outboard jetdrive marine system of claim 6, further comprising: a bucket assemblyadapted to be mounted to a jet drive unit for receiving a water exhaustfrom said jet drive unit, said bucket assembly having a bucket housing,said bucket housing having a first exhaust, and at least a secondexhaust; the at least second exhaust including a first vent and a secondvent mounted to said bucket housing, said bucket housing having anentrance port for receiving said water exhaust, said first vent beingdisposed on the housing along a first axis and said second vent beingdisposed on the housing along a second axis, the first axis intersectingthe second axis; and a bucket rotatably mounted on said bucket housingat said first exhaust and being rotatable relative to said first exhaustbetween an open position and a closed position, said bucket deflectingwater entering said entrance port to said first and second vents when ina closed position.
 8. The outboard jet drive marine system for a boat ofclaim 7, wherein said bucket housing has a bottom, the first vent andsecond vent being disposed along a circumference of said bucket housingaway from the bottom.
 9. The outboard jet drive marine system for a boatof claim 7, further comprising a first plenum and a second plenum incommunication with the interior of said bucket, said first plenum andsaid second plenum extending to the bottom of said bucket housing whensaid bucket is in the closed position.
 10. The outboard jet drive marinesystem for a boat of claim 9, wherein each said plenum extends at asubstantially obtuse angle to said at least one of said first and secondvents.
 11. The outboard jet drive marine system of claim 7, wherein saidbucket causes said first vent to be in fluid communication with saidsecond vent, when said bucket is in the closed position.
 12. An outboardjet drive marine system for a boat comprising: a bucket assembly adaptedto be mounted to a jet drive unit for receiving a water exhaust fromsaid jet drive unit, said bucket assembly having a bucket housing, saidbucket housing having a first exhaust and at least a second exhaust, theat least second exhaust including a frame disposed within said housingand a vane disposed within said frame for directing said water exhausttowards said boat at an angle to direct the water below said boat; and abucket rotatably mounted on said bucket housing at said first exhaustand being rotatable between an open position and a closed position, saidbucket allowing water to exit said first exhaust when in the openposition and deflecting water entering said entrance port to said secondexhaust when in the closed position.
 13. The outboard jet drive marinesystem for a boat of claim 12, wherein said vane is disposed within thesaid frame at an angle relative to a plane in which a bottom of saidboat resides.
 14. The outboard jet drive marine system for a boat ofclaim 12, further comprising at least a second vane disposed within saidframe and intersecting said first vane to form a plurality of plenumwithin said frame.
 15. The outboard jet drive marine system for a boatof claim 12, further comprising at least a second plenum communicatingwith the interior of said bucket, said at least second plenum extendingat least to the bottom of said bucket housing when said bucket is in theclosed position.
 16. The outboard jet drive marine system for a boat ofclaim 15, wherein each said plenum extends at a substantially obtuseangle to said frame.
 17. The outboard jet drive marine system for a boatof claim 12, wherein said bucket is convex.
 18. The outboard jet drivemarine system for a boat of claim 12, wherein said at least secondplenum is tapered.